A method for manufacturing an optical disc apparatus including: reading by an optical pickup head a medium on which signals are recorded with appropriate optical power; leading an RF signal corresponding to the recorded signal obtained from the medium by the reading by the optical pickup head to a β value calculation circuit and calculating a β value; and storing the calculated β value as a circuit offset into a circuit offset storage section, and an optical disc apparatus thus manufactured are disclosed.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A method for manufacturing an optical disc apparatus, comprising: reading by an optical pickup head a reference medium on which signals are recorded with appropriate optical power, to obtain an RF signal; leading the RF signal obtained from the reference medium by the reading by the optical pickup head to a β value calculation circuit having an inherent offset; estimating a value of the inherent offset by calculating a β value in the β value calculation circuit using the RF signal; and storing the value of the inherent offset into a circuit offset storage section that is a non-volatile memory.
2. The method for manufacturing an optical disc apparatus as set forth in claim 1 , wherein the calculating the β value calculates the β value as a digital value.
3. The method for manufacturing an optical disc apparatus as set forth in claim 2 , wherein the storing the value of the inherent offset into the circuit offset storage section stores the value of the inherent offset as a digital value into the circuit offset storage section.
4. The method for manufacturing an optical disc apparatus as set forth in claim 1 , wherein the reference medium on which signals are recorded with appropriate optical power is prepared in plural in different kinds or from different manufacturers of media, and the reading the reference medium by the optical pickup head, the leading the RF signal to the β value calculation circuit, the estimating the value of the inherent offset, and the storing into the circuit offset storage section are performed for each of the reference medium, the value of the inherent offset being store into the circuit offset storage section in correspondence with a kind of medium or a manufacturer of medium.
5. An optical disc apparatus, comprising: an optical writing section configured to record a signal onto a recording medium with writing optical power changed; an optical reading section configured to read the signal from the recording medium, to obtain an RF signal; a β value calculation circuit, having an inherent offset, configured to calculate a β value using the RF signal; a circuit offset storage section configured to prestore a value of the inherent offset possessed by the β value calculation circuit; a subtracting section configured to subtract the value of the inherent offset from the β value to create a corrected β value; and a writing optical power setting section configured to set appropriate writing optical power based on the corrected β value.
6. The optical disc apparatus as set forth in claim 5 , wherein the β value calculation circuit is configured to calculate the β value as a digital value, and wherein the circuit offset storage section is configured to prestore the value of the inherent offset as a digital value.
7. The optical disc apparatus as set forth in claim 5 , wherein the circuit offset storage section is capable of holding a plurality of values of the inherent offset, the plurality of values of the inherent offset being in correspondence with different kinds of media or manufacturers of media respectively, and one of the plurality of values of the inherent offset selected based on a recognized kind of medium or manufacturer is used in the subtracting section.
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July 28, 2004
April 1, 2008
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